1. Field of the Invention
The invention relates to a method to determine the risk of collision for two mutually movable bodies, which cooperate with transducers for continuous monitoring of the positions of the bodies during a motion. Suitably in case of risk for collision a signal can be delivered, which automatically brakes or stops the motion of the bodies so that collision is prevented. Furthermore it relates to a device for carrying out the method.
The invention can be used in many circumstances, where two or more bodies can move arbitrarily and independently of each other. As an example equipment can be mentioned where several apparatus parts shall be set relative to a patient table, which is also movable in itself, hoisting cranes, overhead cranes, industrial robots and the like, which can move relative to fixed construction or other movable bodies. In such cases, where two or more bodies are included, which can move in several directions, it is often difficult to predict all situations when collision may occur. An operator, who controls and supervises the motion of the bodies, can often not see simultaneously all movable parts and with the new combinations of mutual positions of the bodies, which can arise collision then may occur in a part of the equipment, while the operator has his attention directed to another part of the equipment.
2. Description of the Prior Art
It has previously been proposed to solve the problem by prescribing conditions for the motion of the bodies, so that only certain motions are allowed, while other motions under given conditions are forbidden. Thus, it is possible in each position of a body to calculate forbidden positions or motion zones of another body. The result of these calculations can then be put into a table or be stored in another manner. For each adjustment then the operator first must look up in the table if a certain setting motion is allowed or not. This is complicated and in spite thereof does not given fully satisfactory results, because the tabled information is only a coarse information and cannot cover all possible mutual positions of the bodies.